diff --git a/sys/dev/usb2/controller/at91dci_atmelarm.c b/sys/dev/usb2/controller/at91dci_atmelarm.c
index d0772fe0f7f..23de204fc05 100644
--- a/sys/dev/usb2/controller/at91dci_atmelarm.c
+++ b/sys/dev/usb2/controller/at91dci_atmelarm.c
@@ -147,6 +147,7 @@ at91_udp_attach(device_t dev)
 
 	/* get all DMA memory */
 
+	sc->sc_dci.sc_bus.parent = dev;
 	if (usb2_bus_mem_alloc_all(&sc->sc_dci.sc_bus,
 	    USB_GET_DMA_TAG(dev), NULL)) {
 		return (ENOMEM);
diff --git a/sys/dev/usb2/controller/ehci2_pci.c b/sys/dev/usb2/controller/ehci2_pci.c
index 41b5c2caf2a..65e4fcefe6e 100644
--- a/sys/dev/usb2/controller/ehci2_pci.c
+++ b/sys/dev/usb2/controller/ehci2_pci.c
@@ -234,6 +234,7 @@ ehci_pci_attach(device_t self)
 	}
 	/* get all DMA memory */
 
+	sc->sc_bus.parent = self;
 	if (usb2_bus_mem_alloc_all(&sc->sc_bus,
 	    USB_GET_DMA_TAG(self), &ehci_iterate_hw_softc)) {
 		return ENOMEM;
diff --git a/sys/dev/usb2/controller/musb2_otg_atmelarm.c b/sys/dev/usb2/controller/musb2_otg_atmelarm.c
index f67de1ed565..de4b58b2f64 100644
--- a/sys/dev/usb2/controller/musb2_otg_atmelarm.c
+++ b/sys/dev/usb2/controller/musb2_otg_atmelarm.c
@@ -104,6 +104,7 @@ musbotg_attach(device_t dev)
 
 	/* get all DMA memory */
 
+	sc->sc_otg.sc_bus.parent = dev;
 	if (usb2_bus_mem_alloc_all(&sc->sc_otg.sc_bus,
 	    USB_GET_DMA_TAG(dev), NULL)) {
 		return (ENOMEM);
diff --git a/sys/dev/usb2/controller/ohci2_atmelarm.c b/sys/dev/usb2/controller/ohci2_atmelarm.c
index cd0d3327115..b440f1490d5 100644
--- a/sys/dev/usb2/controller/ohci2_atmelarm.c
+++ b/sys/dev/usb2/controller/ohci2_atmelarm.c
@@ -75,6 +75,7 @@ ohci_atmelarm_attach(device_t dev)
 	}
 	/* get all DMA memory */
 
+	sc->sc_ohci.sc_bus.parent = dev;
 	if (usb2_bus_mem_alloc_all(&sc->sc_ohci.sc_bus,
 	    USB_GET_DMA_TAG(dev), &ohci_iterate_hw_softc)) {
 		return ENOMEM;
diff --git a/sys/dev/usb2/controller/ohci2_pci.c b/sys/dev/usb2/controller/ohci2_pci.c
index fe84e9c0fef..990c8498329 100644
--- a/sys/dev/usb2/controller/ohci2_pci.c
+++ b/sys/dev/usb2/controller/ohci2_pci.c
@@ -202,6 +202,7 @@ ohci_pci_attach(device_t self)
 	}
 	/* get all DMA memory */
 
+	sc->sc_bus.parent = self;
 	if (usb2_bus_mem_alloc_all(&sc->sc_bus, USB_GET_DMA_TAG(self),
 	    &ohci_iterate_hw_softc)) {
 		return ENOMEM;
diff --git a/sys/dev/usb2/controller/uhci2_pci.c b/sys/dev/usb2/controller/uhci2_pci.c
index 44e0b591de2..9baf42bd1c0 100644
--- a/sys/dev/usb2/controller/uhci2_pci.c
+++ b/sys/dev/usb2/controller/uhci2_pci.c
@@ -253,6 +253,7 @@ uhci_pci_attach(device_t self)
 	}
 	/* get all DMA memory */
 
+	sc->sc_bus.parent = self;
 	if (usb2_bus_mem_alloc_all(&sc->sc_bus, USB_GET_DMA_TAG(self),
 	    &uhci_iterate_hw_softc)) {
 		return ENOMEM;
diff --git a/sys/dev/usb2/controller/usb2_bus.h b/sys/dev/usb2/controller/usb2_bus.h
index c58c986e7b0..d9dc74ee0f9 100644
--- a/sys/dev/usb2/controller/usb2_bus.h
+++ b/sys/dev/usb2/controller/usb2_bus.h
@@ -59,6 +59,7 @@ struct usb2_bus {
 	struct usb2_perm perm;
 	struct usb2_xfer_queue intr_q;
 
+	device_t parent;
 	device_t bdev;			/* filled by HC driver */
 
 	struct usb2_dma_parent_tag dma_parent_tag[1];
diff --git a/sys/dev/usb2/controller/usb2_controller.c b/sys/dev/usb2/controller/usb2_controller.c
index 7c3ea896e44..5dd517d67d1 100644
--- a/sys/dev/usb2/controller/usb2_controller.c
+++ b/sys/dev/usb2/controller/usb2_controller.c
@@ -430,7 +430,7 @@ usb2_bus_mem_alloc_all(struct usb2_bus *bus, bus_dma_tag_t dmat,
 
 	bus->devices_max = USB_MAX_DEVICES;
 
-	mtx_init(&bus->bus_mtx, "USB bus lock",
+	mtx_init(&bus->bus_mtx, device_get_nameunit(bus->parent),
 	    NULL, MTX_DEF | MTX_RECURSE);
 
 	TAILQ_INIT(&bus->intr_q.head);
diff --git a/sys/dev/usb2/controller/uss820dci_atmelarm.c b/sys/dev/usb2/controller/uss820dci_atmelarm.c
index 3a1eb16f4c6..8e92ffb4f9e 100644
--- a/sys/dev/usb2/controller/uss820dci_atmelarm.c
+++ b/sys/dev/usb2/controller/uss820dci_atmelarm.c
@@ -140,6 +140,7 @@ uss820_atmelarm_attach(device_t dev)
 	}
 	/* get all DMA memory */
 
+	sc->sc_bus.parent = dev;
 	if (usb2_bus_mem_alloc_all(&sc->sc_bus,
 	    USB_GET_DMA_TAG(dev), NULL)) {
 		return (ENOMEM);